An LDAP database can be distributed over multiple servers. If the requested information is not on the current server, the LDAP v3 standard provides a mechanism for the server to return a referral to the client that informs the client of an alternate server. (This feature is also included in some LDAP v2-compliant servers.)
ColdFusion can handle referrals automatically. If you specify a nonzero referral attribute in the cfldap tag, ColdFusion sends the request to the server specified in the referral.
The referral attribute value specifies the number of referrals allowed for the request. For example, if the referral attribute is 1, and server A sends a referral to server B, which then sends a referral to server C, ColdFusion returns an error. If the referral attribute is 2, and server C has the information, the LDAP request succeeds. The value to use depends on the topology of the distributed LDAP directory, the importance of response speed, and the value of response completeness.
When ColdFusion follows a referral, the rebind attribute specifies whether ColdFusion uses the cfldap tag login information in the request to the new server. The default, No, sends an anonymous login to the server.